Blender Video Editing, Newbie, channel 0
Thanks

I'm not sure of some of the "blender language" yet, but my problem was because I dropped a video in and then pressed space (as play).

At the top right pane of the screen is a panel that is described as "Scene" and has a drop down panel that is titled (?) Dimensions. I think this is what Leander described, but there appears to be nothing described as a "Properties Area". (What should I read to understand this?)

My problem was fixed by changing the "frame start" and "frame end" in said Dimensions drop-down panel to be something appropriate for the video I had dragged in.

I had referred to this as a channel 0 being the sort-of-blank channel underneath channel 1. I'm not yet sure of its proper name. But I see now that the "frame start", "frame end" combo selects a display area in the background of the channels, and that the area I refer to is in the foreground, and contains the text for markers and perhaps other things...

Thanks very much for the pointers, I'm hopefully on my way now.